The Sion astronomical clock is an astronomical clock at the town hall of Sion in the canton of Valais, Switzerland. The clock was first installed in 1667–68; the present mechanism dates from 1902.[1][2]
The clock has five dials: on the two lateral sides of the clock tower, there are 12-hour dials. The principal dial on the front of the tower indicates, from the outer to the inner ring:[2]
The position of the Sun in the zodiac and the month are both indicated by a hand with a golden sun. The other end of this hand, with a star, indicates the constellation which passes through the meridian at Sion in the middle of the night.[2]
The two smaller dials underneath the principal dial indicate the day of the week, represented by an illustration of its classical deity, and the lunar phase by means of a rotating moon ball.[1][2]
46°14′02″N 7°21′38″E / 46.23378°N 7.36061°E / 46.23378; 7.36061